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FemtoMck Ultra-Low Jitter Audio Clock
FemtoMck Ultra-Low Jitter Audio Clock
4.0 / 5.0
(1) 1 total reviews
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Introduction
Standard audiophile grade clocks with excellent phase noise performance and competitive price. Default configuration for FifoPiQ7 III and TransportPi Digi Pro. Great for all audio applications that require enhanced clocks.
Features
- Ultra-low jitter audio clock.
- Dual shield cans on both top and bottom side of PCB for the best possible EMI noise suppression.
- Enhanced internal noise filtering networks for a cleaner power supply.
- 3.3V ultracapacitor or battery direct power supply would be preferred to improve the performance.
- Featuring an OE standby function.
- One-year limited warranty.
Phase Noise
| dBc/Hz | 45.1584 MHz | 49.1520 MHz | 90.3168 MHz | 98.3040 MHz |
| 0.1 Hz | -36 | -35 | -28 | -25 |
| 1 Hz | -73 | -72 | -60 | -59 |
| 10 Hz | -102 | -102 | -91 | -90 |
| 100 Hz | -132 | -131 | -116 | -115 |
| 1 kHz | -158 | -155 | -144 | -143 |
| 10 kHz | -166 | -163 | -160 | -164 |
| 100kHz | -167 | -164 | -165 | -165 |
| 1 MHz | -168 | -165 | -167 | -166 |
| 10 MHz | -168 | -166 | -167 | -167 |
Pin connections
| Pin# | Functions |
| 1 | OE (1: Output, 0: High Z) |
| 2 | GND |
| 3 | Output (LVCMOS) |
| 4 | Vcc 3.3V |
Operation Notes
- Reversing the installation orientation will result in permanent damage to the clock, which is not covered by the warranty. Please pay exercise caution when installing the FemtoMck clocks.
- The pins of the FemtoMck clock are machined from solid-core copper and are gold-plated. Exercise extreme caution during installation, as these pins are prone to breaking if bent. Broken pins are not covered by the warranty and will incur re-work and re-testing fees. Damage to the shield can will also void the warranty.
- FemtoMck crystals require an extended period to achieve optimal phase noise performance. For new clocks, please refrain from serious listening until they have operated continuously for more than 24 hours. Further improvements can continue to develop over weeks or months of continuous operation.
- Power supplies are crucial for maintaining the FemtoMck's optimal phase noise performance and sound quality. Linear power supplies may serve as an entry-level option. The best power supplies are direct ultra-capacitor supplies or LiFePO4 battery supplies. Below is a list of recommended power supplies for FemtoMck, ranked by performance.
#1: UcPure Pro 3.3V with 3000F ultracapacitors
#2: LifePO4 Mini Pro 3.3V with UcConditioner 3.3V
#3: PurePi 3.3V with UcConditioner 3.3V
#4: LifePO4 Mini 3.3V or PurePi 3.3V
#5: LinearPi/Pro 3.3V with UcConditioner 3.3V
#6: LinearPi 3.3V
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I made a DIY external clock source for an ES9038Pro DAC, and I have tried only a few different crystal oscillators. No surprise that the best is the SC-Pure. The FemtoMck is clearly better than similarly priced Crystek 957-25 oscillators that are about the same price. Every system and listener is different, but I would rate the FemtoMck to be about midway between the SC-Pure and the Crysteks mounted on Ian's noise-suppressing socket adaptors. Importantly, the FemtoMck is better at preventing sibilance in upper frequencies (from poor recording tech on through to poor listening room acoustics). In summary, the FemtoMck is the best value I've seen or heard. Four stars simply because they're very good; just not quite as transparent as the SC-Pure oscillators (at about 7X the price).
